1998 225 Merc Motor HELP!!

**Lauren** · 05-19-2018, 03:02 PM

Thank you!!

**Lauren** · 05-19-2018, 03:05 PM

Thank you!! I just saw your location and we are actually in Chapmansboro which won't be far from you at all!!!

**Merc 2.5** · 05-19-2018, 07:58 PM

I gotta chance to meet with Lauren and Brad. Looked motor over. It has no numbers on block except r p on Welch plug does look to be a painted Promax also has has Promax sound to it little bit. What is stock compression for 225 Promax? Would it have idle reliefs?

**bullet123** · 05-19-2018, 08:02 PM

No idle reliefs slots. 175 and 150 had idle reliefs . Should be 125 range.

**bullet123** · 05-19-2018, 08:05 PM

Only way I would know to tell for sure if it’s a promax since it’s black, is to pull intake and see if it’s a 7 petal and pull a head to look at porting

**Merc 2.5** · 05-19-2018, 08:07 PM

I got 106 -115. Fire on all 6 on hose. Dnt sound like it's missing on hose. It's is leaking between block halves. Seems to b seal leaking not top cap seal. I'm afraid it's not enough compression. This is gauge I've tested all mine with. Did not get chance to do a leak down also he told me he has been slowly losing rpm. Started running 6200ish I believe and now down to 5200 and now Dnt wanna take off

**Merc 2.5** · 05-19-2018, 08:13 PM

Did check fire with light on hose doesn't mean it won't lose it under load. But is this compression up to par for this motor. Or is this the reason he is losing rpms?

**Merc 2.5** · 05-19-2018, 08:16 PM

Sry #2 or 4 was 100lbs

**bullet123** · 05-19-2018, 08:19 PM

Leaking on both sides of block? Look like it got hot? Compression seems pretty low for any healthy
v6 merc unless it’s a slot motor. I would not be surprised if it’s a 175 fishing block

**Merc 2.5** · 05-19-2018, 08:19 PM

I didn't get pull head as I wanted to. Do you no if bolt patten is same for 5 and 7 pedal or are the bolts n different places for 7?

**Merc 2.5** · 05-19-2018, 08:22 PM

Actually there were a few air bubbles n paint but no discoloring and yes both sides

**Merc 2.5** · 05-19-2018, 08:26 PM

Nothing jumped out at me like it had ran hot

**bullet123** · 05-19-2018, 08:27 PM

IMO. Motor is unhealthy. Either tear it down determine what you have and fix or just count your losses and try and trade it in.

**Merc 2.5** · 05-19-2018, 08:31 PM

And that was bout my exact words. If it is a Promax. Should have a gud platform to start with. I think it's just lacking compression/power under load. Mine did same thing with low compression